>>90892816The manga goes way past the anime and is just kinda bonkers. Long story short is there's a massive alien invasion and our heroes save the day.
As for was it good? If you enjoyed the spectacle of Gantz then you'll probably enjoy reading the manga. The ending itself is kinda flat, doesn't really do enough to resolve every characters story, and also just sorta hits a button for "The End."
Without any spoilers, it's kinda like when a RomCom ends when the MCs kiss. You're not mad at the end, but there could have been so much more.
